Clinical Validation of a Novel Handsfree Doppler Ultrasound Device, RescueDoppler, in Adult Cardiac Surgery Patients

The goal of this study is to evaluate a new device called RescueDoppler (RD), which measures continuous blood flow in the common carotid artery. The device is handsfree and operator- independent. The research will involve adult participants who are undergoing cardiac surgery at St. Olavs Hospital in Trondheim, Norway. The aim of the first part of the study is to evaluate the RescueDoppler system in comparison to conventional Doppler ultrasound, which is commonly used to assess blood flow in carotid artery. The researchers will measure blood flow in the left common carotid artery in three different reversible situations: * when the participant is resting, * when there is increased blood flow (passive leg raise) and * when there is decreased blood flow ( breathing against a resistance). We will initially conduct the investigation using the conventional Doppler. Subsequently, we will repeat the interventions with the RD patch positioned over the left common carotid artery. The RD patch will stay positioned over the left carotid artery after the completion of the comparison phase. In the subsequent phase, the focus will shift to transitions between normal blood flow and low or absent blood flow and the RescueDopplers ability to detect. During cardiac surgery, participants will experience fluctuations in blood pressure, pulse, and circulation. By measuring blood flow with the RescueDoppler during these variations, researchers will evaluate the device´s capability to monitor different blood flow patterns. Overall, the study aims to provide valuable insights into the effectiveness of the RescueDoppler in a clinical setting where changes in blood flow are expected.